Away from the glare of the blinding lights of civilization, the unobstructed view of the night sky makes you feel as if you are standing on the shore of eternity. But there is a place on Earth where the views extend a little farther than anywhere else.
Researchers have measured the clarity of stars at a large research station in Antarctica, finding that it exceeds current top astronomy hotspots. The result may not be surprising, but for most of us it is a little disappointing.
Dome A is the tallest ice dome on the Antarctic Polar Plateau. Rising more than 4 kilometers (over 13,000 feet) above sea level and sitting approximately 1,200 kilometers (750 miles) from the ocean in the middle of the coldest continent, it is bound to become icy.
In fact, temperatures can drop to -90 degrees Celsius (-1
However, if that doesn’t deter you, the rewards may just be worth the effort.
This frozen peak provides an astronomical perspective like no other, in view of being relatively unharmed by spots of light pollution, interference from numerous passing satellites, or even by an accidental passing cloud.
“A telescope located in Dome A could perform a similar telescope located on any other astronomical object on the planet,” said Paul Hickson, an astronomer at the University of British Columbia (UBC).
“The combination of high altitude, low temperature, long periods of continuous darkness and an extremely stable atmosphere makes Dome A a very attractive place for optical and infrared astronomy. The telescope located there would have sharper images and could detect weaker objects.”
If you really want to see further into the depths of space and time, you will have to escape from the nearest part of the atmosphere called the boundary layer. The gases that make up this thin blanket are not just clogged with dust and moisture – the heat of the earth makes it shiny, making the stars seem to blink.
One way to determine this disturbing oscillation is through a figure called astronomical vision, which is a description of the apparent diameter of the light source in units called arcseconds.
This number means the difference in distinguishing one light point as one source or multiple, so that the less turbulence and clearer the vision, the smaller the object (and therefore the shorter arc is the second).
Currently, the best ground-based telescopes available to astronomers are on hills where the boundary layer is relatively thin.
Today, Chile’s high-lying Atacama Desert is considered one of the best places for telescopes, home to the large millimeter Atacama massif for radio imaging, and soon to host the insanely giant Magellan telescope, a beast to surpass Hubble.
In this corner of the globe, atmospheric conditions can provide astronomical vision of regular figures with a low value of about 0.66 arcseconds. On some clear nights, that number may even drop by about half in a few hours here and there.
Hickson and his colleagues measured the astronomical vision of Kunlun Station on Dome A, a Chinese research post that is already considered an attractive site for astronomers.
Another icy inner Antarctic object, called Dome C, already had approximate values of 0.23 to 0.36 arcseconds. But no one still had a good measure for those from Dome A.
Placing their measuring equipment 8 meters from the ground, the team recorded numbers of only 0.13 arc seconds, which puts it in the ball of observatories outside the atmosphere. In fact, the number reflects a boundary layer only 14 meters thick.
“After a decade of circumstantial evidence and theoretical reasoning, we finally have direct observation evidence of exceptionally good conditions at Dome A,” said astronomer Michael Ashley of the University of New South Wales in Australia.
Before packing your ripples and your reliable old telescope for a starry night, you need to know the conditions of Dome A do not only threaten frost. Your equipment must be the most modern.
“Our telescope automatically observed the sky completely at an unmanned station in Antarctica for seven months, with air temperatures dropping to -75 degrees Celsius at times. This in itself is a technological breakthrough,” said the study’s lead author, the astronomer. UBC Bin Ma,
Even with advanced technology that could be used from somewhere warmer, the team had to deal with the scourge of ice. Overcoming the obstacle of extreme temperatures can help see more, by about 12 percent.
While most of this reading will never see the conditions for observing the clear sky of Dome A, we can all benefit from the universal insights of the great astronomical projects that are being created there in the future.
This study was published in nature,,